Immediately southeast of Letterfrack, Connemara National Park spans 2000 dramatic hectares of bog, mountain and heath. The visitor centre, in a beautiful setting off a parking area 300m south of the Letterfrack crossroads, offers an introduction to the park's flora, fauna and geology, and visitors can scrutinise maps and various trails here before heading out into the park. Various types of flora and fauna native to the area are explained, including the elephant hawkmoth and red deer. There's a tearoom.
The park encloses a number of the Twelve Bens, including Bencullagh, Benbrack and Benbaun. The heart of the park is Gleann Mór (Big Glen), through which the River Polladirk flows. There's fine walking up the glen and over the surrounding mountains. There are also short self-guided walks and, if the Bens look too daunting, you can hike up Diamond Hill nearby.
Guided nature walks led by park rangers depart from the visitor centre several days a week.